Dell Force10 E600i FTOS Version 8.4.1.5 Configuration Guide for ExaScale - Page 675

Loopback interfaces also assist in the OSPF process. OSPF will pick the highest interface address as the router-id and a loopback interface address has a higher precedence than other interface addresses. The following text gives an example of the show ip ospf process-id interface command with a Loopback interface. FTOS#show ip ospf 1 int GigabitEthernet 13/23 is up, line protocol is up Internet Address 10.168.0.1/24, Area 0.0.0.1 Process ID 1, Router ID 10.168.253.2, Network Type BROADCAST, Cost: 1 Transmit Delay is 1 sec, State DROTHER, Priority 1 Designated Router (ID) 10.168.253.5, Interface address 10.168.0.4 Backup Designated Router (ID) 192.168.253.3, Interface address 10.168.0.2 Timer intervals configured, Hello 10, Dead 40, Wait 40, Retransmit 5 Hello due in 00:00:08 Neighbor Count is 3, Adjacent neighbor count is 2 Adjacent with neighbor 10.168.253.5 (Designated Router) Adjacent with neighbor 10.168.253.3 (Backup Designated Router) Loopback 0 is up, line protocol is up Internet Address 10.168.253.2/32, Area 0.0.0.1 Process ID 1, Router ID 10.168.253.2, Network Type LOOPBACK, Cost: 1 Loopback interface is treated as a stub Host. Configure stub areas OSPF supports different types of LSAs to help reduce the amount of router processing within the areas. Type 5 LSAs are not flooded into stub areas; the Area Border Router (ABR) advertises a default route into the stub area to which it is attached. Stub area routers use the default route to reach external destinations To ensure connectivity in your OSPFv2 network, never configure the backbone area as a stub area. Use these commands in the following sequence, starting in EXEC Privilege mode to configure a stub area. Step 1 Command Syntax Command Mode show ip ospf process-id [vrf vrf name] database database-summary EXEC Privilege 2 configure EXEC Privilege 3 router ospf CONFIGURATION process-id [vrf {vrf name}] Usage Review all areas after they were configured to determine which areas are NOT receiving type 5 LSAs. vrf name: Show only the OSPF information tied to the VRF process. Enter the CONFIGURATION mode. Enter the ROUTER OSPF mode. Process ID is the ID assigned when configuring OSPFv2 globally. vrf name: Enter the VRF key word and instance name to tie the OSPF instance to the VRF. All network commands under this OSPF instance are subsequently tied to the VRF instance. Open Shortest Path First (OSPFv2 and OSPFv3) | 675